The New Sudoku Players' Forum

[Yogi]

39..7.18.......6....648....5.8...721.7..2..562..7.58.3...9.3.6.......2..6..257..8

Another one that Sourceforge SE rates as 10.3 I still haven't been able to activate Sukaku.
No doubt someone can solve this puzzle, but what would be a more normal rating?

[Yogi]

Code: Select all

+----------------------+----------------------+----------------------+
| 3      9      245    | 56     7      26     | 1      8      245    |
| 1478   12458  12457  | 135    139    129    | 6      3479   24579  |
| 17     125    6      | 4      8      129    | 359    379    2579   |
+----------------------+----------------------+----------------------+
| 5      346    8      | 36     3469   469    | 7      2      1      |
| 149    7      1349   | 138    2      1489   | 49     5      6      |
| 2      146    149    | 7      1469   5      | 8      49     3      |
+----------------------+----------------------+----------------------+
| 1478   12458  12457  | 9      14     3      | 45     6      457    |
| 14789  13458  134579 | 168    146    1468   | 2      13479  4579   |
| 6      134    1349   | 2      5      7      | 349    1349   8      |
+----------------------+----------------------+----------------------+


[yzfwsf]

SE7.9 by version 1.2.1

Junior Exocet:Base Cells-r2c8,r3c8;Target Cells-r4c7,r4c9,r9c7,r9c9;Cross Cells-r149c123456 Locked Member in T1: 7 Locked Member in T2: 3
"S" Cells Need Include:4r6,9r6,
Locked Member In Target:r8c8<>7
Mirror Check:r9c7<>49
True Base digits seen by base cells or both targets: r3c7<>3,r8c8<>3,r9c2<>3,r9c3<>3,r9c8<>3r2c9<>7,r3c9<>7,r8c8<>7
JE Version POM Test:r78c9,r2c8,r9c7<>4,r23c9,r8c8<>7,r238c8,r58c3,r9c7<>9
Base disappear from both targets(opposite mirror nodes): r2c8<>49 r3c8<>9

NT=>stte

[denis_berthier]

39..7.18.......6....648....5.8...721.7..2..562..7.58.3...9.3.6.......2..6..257..8

Another one that Sourceforge SE rates as 10.3 I still haven't been able to activate Sukaku.
No doubt someone can solve this puzzle, but what would be a more normal rating?

SER rates it 7.9

A better rating is gW3.
As we're talking of rating, there's no need of using any exotic pattern.

Code: Select all

Resolution state after Singles and whips[1]:
   +----------------------+----------------------+----------------------+
   ! 3      9      245    ! 56     7      26     ! 1      8      245    !
   ! 1478   12458  12457  ! 135    139    129    ! 6      479    24579  !
   ! 17     125    6      ! 4      8      129    ! 359    379    2579   !
   +----------------------+----------------------+----------------------+
   ! 5      346    8      ! 36     3469   469    ! 7      2      1      !
   ! 149    7      1349   ! 138    2      148    ! 49     5      6      !
   ! 2      146    149    ! 7      146    5      ! 8      49     3      !
   +----------------------+----------------------+----------------------+
   ! 1478   12458  12457  ! 9      14     3      ! 45     6      457    !
   ! 1479   1345   134579 ! 168    146    1468   ! 2      13479  4579   !
   ! 6      134    1349   ! 2      5      7      ! 349    1349   8      !
   +----------------------+----------------------+----------------------+
165 candidates

hidden-pairs-in-a-column: c5{n3 n9}{r2 r4} ==> r4c5≠6, r4c5≠4, r2c5≠1
finned-x-wing-in-rows: n9{r6 r9}{c3 c8} ==> r8c8≠9
z-chain[3]: b6n9{r6c8 r5c7} - c1n9{r5 r8} - c9n9{r8 .} ==> r2c8≠9, r3c8≠9
g-whip[3]: b6n4{r6c8 r5c7} - r9n4{c7 c123} - c1n4{r7 .} ==> r2c8≠4
singles ==> r2c8=7, r3c8=3, r9c7=3, r3c1=7
whip[1]: b3n4{r2c9 .} ==> r7c9≠4, r8c9≠4
x-wing-in-rows: n9{r6 r9}{c3 c8} ==> r8c3≠9, r5c3≠9
naked-triplets-in-a-block: b7{r8c1 r9c2 r9c3}{n9 n1 n4} ==> r8c3≠4, r8c3≠1, r8c2≠4, r8c2≠1, r7c3≠4, r7c3≠1, r7c2≠4, r7c2≠1, r7c1≠4, r7c1≠1
stte

[P.O.]

a Pattern Overlay Method solution:

Code: Select all

3       9       245     56      7       26      1       8       245             
1478    12458   12457   135     139     129     6       3479    24579           
17      125     6       4       8       129     359     379     2579             
5       346     8       36      3469    469     7       2       1               
149     7       1349    138     2       1489    49      5       6               
2       146     149     7       1469    5       8       49      3               
1478    12458   12457   9       14      3       45      6       457             
14789   13458   134579  168     146     1468    2       13479   4579             
6       134     1349    2       5       7       349     1349    8               

these cells are not in any valid template for the values considered:

  r2c8 <> 3
  r2c8 r7c9 r8c9 <> 4
  r8c1 r8c2 <> 8
  r2c8 r3c8 r5c6 r6c5 r8c8 <> 9
 


bte.

Hidden Text: Show

Code: Select all

( n7r2c8   n3r3c8   n3r9c7   n7r3c1 )
TRIPLET COL: ((6 5 5) (1 4 6)) ((7 5 8) (1 4)) ((8 5 8) (1 4 6))
(((2 5 2) (1 3 9)) ((4 5 5) (3 4 6 9)))
TRIPLET BOX: ((8 1 7) (1 4 9)) ((9 2 7) (1 4)) ((9 3 7) (1 4 9))
(((7 1 7) (1 4 8)) ((7 2 7) (1 2 4 5 8)) ((7 3 7) (1 2 4 5 7))
 ((8 2 7) (1 3 4 5)) ((8 3 7) (1 3 4 5 7 9)))
( n8r7c1   n1r7c5   n4r7c7   n5r3c7   n8r2c2   n9r5c7   n4r6c8
  n1r8c8   n9r9c8   n6r6c5   n4r8c5   n3r4c4   n9r4c5   n4r4c6
  n1r6c2   n9r6c3   n9r8c1   n4r9c2   n1r9c3   n3r2c5   n2r3c2
  n9r3c9   n6r4c2   n4r5c1   n3r5c3   n5r7c2   n7r7c9   n3r8c2
  n7r8c3   n5r8c9   n1r2c1   n5r2c4   n1r3c6   n8r5c6   n2r7c3
  n6r8c6   n6r1c4   n2r1c6   n4r1c9   n4r2c3   n9r2c6   n2r2c9
  n1r5c4   n8r8c4   n5r1c3 )
3 9 5   6 7 2   1 8 4
1 8 4   5 3 9   6 7 2
7 2 6   4 8 1   5 3 9
5 6 8   3 9 4   7 2 1
4 7 3   1 2 8   9 5 6
2 1 9   7 6 5   8 4 3
8 5 2   9 1 3   4 6 7
9 3 7   8 4 6   2 1 5
6 4 1   2 5 7   3 9 8


i don't know if there is an easy way to show the justification for the eliminations, anyway here is a attempt to do so;
the elimination of some candidates can be justified by basic patterns:
an intersection eliminates 3 in r2c8
an intersection eliminates 8 in r8c1 r8c2
an intersection eliminates 9 in r5c6 r6c5
a finned x-wing eliminates 9 in r8c8
that make 6 eliminations out of 11, i don't know if the are known patterns that eliminate the three 4 and the two others 9

the cells are indexed from 1 to 81 in row order
for each value the number of valid templates: (42 8 9 50 11 6 9 4 11)
for each value the cells, with a candidate for that value, that are not in any of the templates: NIL NIL (17) (17 63 72) NIL NIL NIL (64 65) (17 26 42 50 71)

as an example i take value 9 because there are only 11 valid templates against 50 for value 4
to read the diagram:
• a value cell
. a candidate cell
- a candidate cell with a candidate for the value considered
above the diagram are the cells of the template

Hidden Text: Show

Code: Select all

(2 18 24 32 43 48 58 64 80)    (2 18 24 32 39 53 58 64 79)    (2 18 24 32 37 53 58 66 79)
    • 9 . . • . • • .              • 9 . . • . • • .              • 9 . . • . • • .
    . . . . - - • - X              . . . . - - • - X              . . . . - - • - X
    . . • • • X - - -              . . • • • X - - -              . . • • • X - - -
    • . • . X - • • •              • . • . X - • • •              • . • . X - • • •
    - • - . • - X • •              - • X . • - - • •              X • - . • - - • •
    • . X • - • • - •              • . - • - • • X •              • . - • - • • X •
    . . . 9 . • . • .              . . . 9 . • . • .              . . . 9 . • . • .
    X . - . . . • - -              X . - . . . • - -              - . X . . . • - -
    • . - • • • - X •              • . - • • • X - •              • . - • • • X - •
 
(2 15 27 32 43 48 58 64 80)    (2 15 27 32 39 53 58 64 79)    (2 15 27 32 37 53 58 66 79)
    • 9 . . • . • • .              • 9 . . • . • • .              • 9 . . • . • • .
    . . . . - X • - -              . . . . - X • - -              . . . . - X • - -
    . . • • • - - - X              . . • • • - - - X              . . • • • - - - X
    • . • . X - • • •              • . • . X - • • •              • . • . X - • • •
    - • - . • - X • •              - • X . • - - • •              X • - . • - - • •
    • . X • - • • - •              • . - • - • • X •              • . - • - • • X •
    . . . 9 . • . • .              . . . 9 . • . • .              . . . 9 . • . • .
    X . - . . . • - -              X . - . . . • - -              - . X . . . • - -
    • . - • • • - X •              • . - • • • X - •              • . - • • • X - •
 
(2 15 25 32 37 53 58 72 75)    (2 14 27 33 43 48 58 64 80)    (2 14 27 33 39 53 58 64 79)
    • 9 . . • . • • .              • 9 . . • . • • .              • 9 . . • . • • .
    . . . . - X • - -              . . . . X - • - -              . . . . X - • - -
    . . • • • - X - -              . . • • • - - - X              . . • • • - - - X
    • . • . X - • • •              • . • . - X • • •              • . • . - X • • •
    X • - . • - - • •              - • - . • - X • •              - • X . • - - • •
    • . - • - • • X •              • . X • - • • - •              • . - • - • • X •
    . . . 9 . • . • .              . . . 9 . • . • .              . . . 9 . • . • .
    - . - . . . • - X              X . - . . . • - -              X . - . . . • - -
    • . X • • • - - •              • . - • • • - X •              • . - • • • X - •
 
(2 14 27 33 37 53 58 66 79)    (2 14 25 33 37 53 58 72 75)
    • 9 . . • . • • .              • 9 . . • . • • .
    . . . . X - • - -              . . . . X - • - -
    . . • • • - - - X              . . • • • - X - -
    • . • . - X • • •              • . • . - X • • •
    X • - . • - - • •              X • - . • - - • •
    • . - • - • • X •              • . - • - • • X •
    . . . 9 . • . • .              . . . 9 . • . • .
    - . X . . . • - -              - . - . . . • - X
    • . - • • • X - •              • . X • • • - - •
 


any attempt to assert 9 in r2c8 or r3c8 results in a contradiction.

[Cenoman]

With two group single digit chains:

Code: Select all

 +--------------------------+---------------------+------------------------+
 |  3      9       245      |  56    7     26     |  1     8      #245     |
 | ^1478   12458   12457    |  135   39    129    |  6     7-49  #*24579   |
 |  17     125     6        |  4     8     129    |  359   37-9   *2579    |
 +--------------------------+---------------------+------------------------+
 |  5      346     8        |  36    39    469    |  7     2       1       |
 |^*149    7       1349     |  138   2     148    |^*49    5       6       |
 |  2      146     149      |  7     146   5      |  8   ^*49      3       |
 +--------------------------+---------------------+------------------------+
 | #1478   12458   12457    |  9     14    3      |  45    6      #457     |
 |#*1479   1345    134579   |  168   146   1468   |  2     13479 #*4579    |
 |  6     #134    #1349     |  2     5     7      | #349  #1349    8       |
 +--------------------------+---------------------+------------------------+

1. (9)r6c8 = r5c7 - r5c1 = r8c1 - r8c9 = r23c9 => -9 r23c8
2. [(4)r6c8 = r5c7 - r5c1 *=* r2c1] = r78c1 - r9c23 = r9c78 - r78c9 = r12c9 => -4 r2c8; lclste

[P.O.]

hi Cenoman, your second chain is very fine, il fallait y penser.
you wrote: With two group single digit chains, as i am investigating the Pattern Overlay Method at the moment that remind me of what i read there:
http://forum.enjoysudoku.com/converting-from-candidate-space-to-pom-space-and-beyond-t4398.html#p31067
a quote from Myth Jellies to whom this method is attributed: '(POM)... finds every single-digit reduction possible at that point in the puzzle. All locked candidates, x-wings, swordfish, jellyfish, finned fish, simple coloring, strong links, multi-coloring, grouped multi-coloring, x-cycles, grouped x-cycles, and franken-fish reductions for any converted digits are found.'
so that’s three more eliminations justified.

[DEFISE]

2. [(4)r6c8 = r5c7 - r5c1 *=* r2c1] = r78c1 - r9c23 = r9c78 - r78c9 = r12c9 => -4 r2c8; lclste

Hi Cenoman,
I don't know the meaning of *=*, so I'm stuck.

[yzfwsf]

If 4r5c7 is true ==> 4r2c2 and 4r78c1 cannot be false at the same time.

Code: Select all

Region Forcing Chain: Each 4 in c1 true in turn will all lead to: r2c8<>4
4r2c1
4r5c1 - 4r5c7 = 4r6c8
4r7c1 - 4r9c23 = 4r9c78 - 4r78c9 = 4r12c9
4r8c1 - 4r9c23 = 4r9c78 - 4r78c9 = 4r12c9

[Cenoman]

2. [(4)r6c8 = r5c7 - r5c1 *=* r2c1] = r78c1 - r9c23 = r9c78 - r78c9 = r12c9 => -4 r2c8; lclste

Hi Cenoman,
I don't know the meaning of *=*, so I'm stuck.

It's just an help to readers. When a chain contains an embedded AIC, the square brackets are linked to the rest of the chain, on one side by a weak link to each endpoint of the embedded AIC (here not explicited, weak links to the target 4r2c8) and on the other side by a strong link to some candidate(s)
needed to complete an internal strong link in the embedded AIC (here the 4s in c1) The *=* is a wink to readers (focusing on which strong link is incomplete ) Writing ... r5c1 = r2c1... would have been correct as well.
For a fully expanded writing, see yzfwsf 's kraken. It is the way I had found the move.

[DEFISE]

Thank’s Cenoman,
but searching on my own for an explanation, I found this one:
4r2c8 true => 4r2c1 false => [(4)r6c8 = r5c7 - r5c1 = r78c1 - r9c23 = r9c78 - r78c9 = r12c9] => 4r2c8 false.

(For those who don't want to go beyond the "basic AIC" level, like me).